1. Field of the Invention
The present invention relates to a wireless access system, and more particularly, to a method and apparatus for detecting a Wi-Fi access point (AP).
2. Related Art
In general, cellular mobile station (or devices) in a cellular network detect or scan Wi-Fi access points (APs) by using the following methods.
1. Manuel detection: When a user turns on a Wi-Fi radio of a cellular device, the cellular device searches for Wi-Fi APs located near a user, i.e., the cellular device.
2. Automatic detection: A cellular network triggers a search command for APs on the basis of specific information. The specific information may be a location, an application, a network preference, quality of service (QoS), etc. According to the search command, the cellular device, i.e., the user, turns on the Wi-Fi radio to search for specific APs located near the user.
However, the aforementioned two methods must perform blind scanning to search for information of APs accessible or usable by the cellular device.
The blind scanning of the cellular device requires an excessive time and power consumption. In addition, it is not guaranteed that an AP is within a coverage in which the blind scanning is performed.
In order to solve the excessive time and power consumption in the blind scanning process, AP detection methods coordinated by a network are proposed.
That is, there are several methods in which a cellular network provides cellular devices with information useful for APs existing inside or outside cell coverage of the cellular device so that the cellular devices can rapidly access to the AP.
Herein, the useful information may be 1) list information of APs existing near a user or inside coverage of a base station and 2) pre-provision WLAN information for rapid network (re)entry of a cellular device to a specific AP.
As described above, the most important time consumed in a process of accessing to the WLAN is a time in which a device searches for an AP.
Accordingly, it has been proposed many methods and solutions for decreasing a time consumed when a device searches for an AP during the device operates in a cellular network.